Method of obtaining temperature changes in gases.



A. S. BATT/TAGE.

TvTETTToTT oT oBTATTTTTTTS TEMPERATURE CHANGES TAT GASES. APPLICATIONFILED DEC.3T I9I5- RENEWED MAR. 26T I9-I9. LEQASO Patented Apr. 29,1919.

Y 2 SHEETS-SHEET l.

.0J H Sh mm A. S. RAIVIAGE.

METHOD 0F OBTAINING TEMPERATURE CHANGES IN GASES.

RENEWED MAR. 26 1919.

APPLICATION FILED DEC.3, 1915.

Patented; Apr. 29,1919

M m u w ALEXANDER S. RAMGE, 0F DETROIT, IVHCHIGAN.

METHOD 0F OBTAINING TEMPERATURE CHAN GES IN GASES.

Specification of Letters Patent.

Patented Apr. 29, 11919.

Application led December 3, 1915, Serial No. 64,913. Renewed March 26,1919. Serial No. 285,385.

To all whom t may concern Be it known that l, ALEXANDER S.

RAMAGE, a subject of the King of Great Britain, residing at Detroit, inthe county of 'Wayne and State of Michigan, have invented certain newand useful improvements in Methods of Obtaining Temperature Changes inGases; and-I do hereby declare the following to be a full, clear, andexact description of the same, reference being had to the accompanyingdrawing, forming part of this specification.

This invention relates generically to a new and improved method ofobtaining temperature changes in gases.

It is well known that when it is desired'to change the temperature of agas by expansion or compression, the nal temperature 'll2 of the gasdepends entirely on the initial temperature T1 multiplied'by theconstant factor, namely, A

in which p, is the initial absolute pressure and p2 is t-he finalabsolute pressure. In the production of heat or cold by the compressionor expansion of gases it has heretofore been necessary to Vacuuminsulate the expansion or compression cylinders or 'use other well knownhigh degrees of insulation, if it is desired to conserve the heat ofcompression or the cold produced by expansion. The necessity for suchhigh insulations is due to the fact that the factor of radiationincreases proportionately with the difference in temperature between theoutside air and the gas being compressed or expanded in the cylinder,and thus the greater the difference in temperature the more excessivethe factor of radiation. Even when the highest degrees of insulationknown are employed, great losses occur in radiation atthe time ofcompression or expansionl of the gas, and as a consequence it liasbeenfound exceedingly diiicult to obtain practically adiabatic results. Thiswill be evident from the fact that, according to the equation the finaltemperature '.l"2 rises or lowers correspondingly with a rise orlowering of the initial temperature T1. and hence, in the case ofcompression, any loss through radiation 'in the initial temperature willhave its proportional effect on the final temperature, and, in the caseof expansion, a gain in heat units in the initial temperature will serveto increase the number of heat units in the gas at its finaltemperature.

According to the present invention, the

temperature of that charge with a corre-v spending increase in thefinaltemperature of the gas.' lConsequently, .if successive chargesfof thevgas are compressed the heatexchange will Iproduce an accumulative risein the initial temperature of the successive charges before compression,and in this inanner practically all the heat of compression isconserved.' If the gas is to be expanded,

the charge of gas undergoing expansion'will absorb heat units radiatedfrom the'next succeeding charge 'to be expanded, thereby bringing downthe initial temperature of the next succeeding charge, so thatsuccessive expansions result in progressively decreasing initialtemperatures' of the charges to be expanded. There will, therefore, be acorrespending decrease in the final temperature of the gas.

Whether charges of gas are being com pressed or expanded, the differencein temperature between the charge surrounding the compression orexpansion cylinder and the outside air is very slight,'compared with thedifference in ten'xperature between the interior of the cylinder and theoutside air. Loss of heat 0r cold by radiation is consequently notpresent to an excessive degree, as in former methods, and the problem ofinsulation is capable of very easy solution.

A preferred form of apparatus for carrying out the improved method ofthe present invention is illustrated in the accompanying i drawings, in`which,-

Figure l is a plan view of an apparatus utilizing the principle of theinvention when it is desired to produce cold by expansion, as in thefractional liquefaction or condensation of gases.

. by a slide valve 26 mounted through Fig. 2 is a plan view ofanapparatus designed for the production of heat by the compression ofgases.

Reference is now made to Fig. ,1' which illustrates an apparatus forcarrying out the principleof the present invention, when it is desiredto produce cold by the expansion of gases. Within chamber 1 is a coil 2,one end 3 of which communicates, as at 4, with the gas inlet 5. rlfheother end 6 ofcoil 2 leads out of' chamber 1 into a second chamber 7 anddirects said gasinto aylinder 8 within chamber 7. rThe discharge outlet9 of cylinder 8 communicates with one end of the."

inner coil 10 of a regenerative coil. The other end of inner coil '10passes out of chamber 7 into chamber 12 'and directs the gas through theinner coil 13 of a second regenerative in chamber 18 is an expansioncylinder 19` so mounted as to leave an air space between the outer wallof the expansion cyhnder and vthe inner wall of chamber 18. Theexpansion cylinder is provided with a piston 20 havlng a piston rod 21which drives a crank, shaft 22. rlfhe gas expanding in cylinder 19 mayperform external Work, and y,for this purpose crank shaft 22 Visprovided with a pulley 23 whereby the power producedby expansion may beutilized for anydesire purpose. rlhe inlet port 24 and outlet port 25 ofthe expansion cylinder are controlled on a valve stem 27 convenientlydriven by on crank shaft 23. rl[`he exhaust from cylinder 19 isconducted into chamber 12 by means of an'exhaust pipe 29 when theexhaust port 25 of the expanded cylinder is opened by the slide valvelower half of chamber 12 the exhaust gas flows into the inlet end 30 ofthe outer coil 14 of the lregenerative coil within chamber 12. Chamber12 is provided with a separating partition 12L adjacent the inlet end 30of said outer coil 14, so as to direct the gas into said outer coil. Thegas flows through coil 14 into the outer coil ,11 of the regenerativecoil within chamber '7 and is discharged the outlet 31 of said' coil 11into the space beneath the partition 7a of said chamber. From chamber 7the exhaust gas passes through outlet pipe 32 surrounding inlet 6 ofthe,incoming gas, back into chamber 1, Where it completely surrounds thecoil 2 w1thin said chamber 1. All of the chambers aretinsulated from theoutside air, by any ordlnary means of insulation, such as felt, mineralwool, or the like, as shown at 35a.

1n all cases of refrigeration of air or gases it 1s necessary to inserta trap at some point in the system of the apparatus, for freezing outthe moisture in the incoming gas before derstood in the art. gas entersthrough inlet 3 into coil 2 of coil to the inlet 15 of a cylinder 16Within chamber 12. The discharge outletl the eccentric 28 26. From the,expanded is first compressed and then cooled by any suitable means orapparatusf-well unrlhe cold compressed chamber 1 wherein the gas issubjected to a preliminary regenerative effect. Circulating through thecoil, the gas passes through inlet 6 into cylinder 8 within chamber 7,then out of cylinder 8 through its out-let 9 and flows through the lnner,coil 10 of the first regenerative coil. The gas next flows through theinner coil 13 of the next regenerative coil, within chamber 12, andthrough the inlet 15 into cylinder 16. The cold compressed oas passesout of cylinder 16 through outlet 17 into the space within chamber 18surrounding expansion cylinder 19.

Assuming that the inlet port 24 of said expansion cylinder be opened bythe valve 2G, the first charge of the cold compressed gas enters thecylinder, driving the piston 20 against external resistance and doingexternal work through the medium of the pulley d 23 on crank shaft 22.During the expansion of the charge of gas within Vcylinder 19, the outerwall of the cylinder is entirely surrounded by the next charge of gas tobe eX- panded, so that any inrush of heat units from the next charge tothe charge undergoing expansion are subtracted from the temperature ofthe next charge, thereby lowering its initial temperature.

The result of lowering the initial temperature of successive charges tobe expanded may be graphically illustrated by the fol? lowing: If theinitial temperature of the first charge of gas undergoing expansionwithin cylinder 19 is 60o F. or 521 absolute, and it enters theexpansion cylinder at .an initial absolute pressure of 150 pounds, thenthe final obsolute temperature of the cxy panded charge in cylinder 19is 521 .56, if it be assumed that the charge of gas is exi panded to apressure of 15 pounds. rlllhis takes place according to the equation:

= 521 X 521 X .56 =292 absolute or- 169 F.

recense.

units radiating from, the compressed gas surrounding the expansioncylinder and absorbed by the charge of gas undergoing expansion wouldhave the effect of lowering the imtial temperature T, o the nextsucceeding charge to be expan ed, and conse quently the finaltemperature T2 of that charge, after expansion, would be much lower thanthe final temperature vof the first charge, after expansion. 'Accordingtothe formula, the temperature of the first charge after expansion wouldbe 521 absolute multii plied by .56, which is equal to 292 absolute or.169O F. The dii'erence in temper# ature between the first charge afterexpansion at a temperature of 169 F.. and the ing charge to drop to. 500absolute or 39" F.,

a diterence of 21 F. between its initial temperature and the initial,temperature of the charge undergoing expansion.' Consequently, thesurrounding charge, on ,being expanded, would drop to a i'naltemperature of 500 absolute multiplied by .56, Swhichequals 280absolute. or *181* F. t will, therefore, be seen that successiveexpansions of charges of gas within the expansion cylinder will have anaccumulative lowering et fect on the initial temperature T, of earchsucceeding charge surrounding the expansion cylinder, because of theheat interchange produced at that time.` By this the inal temperature ofthe gas in the 'system can be lowered to a much greater degree than hasheretofore been possible, the temperature produced being almosttheoretical. The only insulation necessary is to cover chamber 18 andeach of the other chambers in the i system with'felt, or mineralwool,,or any other ordinary insulating material.

rlihe cold expanded gas from cylinder 19 passes through outlet pipe 29into chamber l2, thence through the outer coil of the regenerative coilwithin said chamber to the outer coilll of the vregenerative coil withinchamber 7, and finally into chamber 1- through outlet pipe 32. The abovedescribed process may be utllized in the fractional liquefaction or con'densation ot' a mixture ot two or more gases, such as water gas. lncarrying out the process the cold produced in the regenerative coilwithin chamber 7 would be of such a degree that the carbonio acid gas orcarbon dioxid C0., would liquety and collect in f cylinder within saidchamber 7. The liquefied gas may be drawn o' by-means of a valve 8u. Themore intensecold in the regenerative coil ywithin chamber 12, wouldliqucfy the carbon monoxid or C() which has linner wallof theI chamber.

a lower critical temperature than carbon dioxid, the carbon monoxidcollecting in cylinder 16 within chamber 12. rl`he liqueiied carbonmono'xd may be `drained od through. `a valve 16a. rllhe hydrogen H whichhas a still lower critical temperature passes out into the expansioncylinder 19.

Referring now t0 Fig. 2 of the drawing: The, compressor cylinder 33 ismounted within an insulated chamber 34 in such manne-r astoleave. anairspace between the outer wall of sai'd compressor cylinder and theWithin the compressor cylinder is av piston 35 having al pis-- ton lrod36'which is driven by apower shaitt 37. Atmospheric air or other asenters the compressor cylinder throught e inlet port i0 and isdischarged out of the outlet port 41, which outlet port conducts theheated exhaust from the compressor cylinder to any suitable externalapplication. llt will be observed that heat units radiating from thecharge undergoing compression within the cylinder will be absorbed bythe next succeeding charge surrounding the cylinder,

'thereby raising the initial temperature of the next .succeeding chargeto be compressed.

l The heat exchange produces an accumulative edect on the initialtemperatures of each s ucceeding charge to be compressed, it belngunderstood, however, that the initial tem- `pera-tures of the chargesrise, instead of fall,

cumulative lowering eect on the initial teml perature @t4 successiveunexp'anded charges,

whereby the temperature "of-.the mixture is reduced by successive stagesso as to separately liquefy and recover said gases.

"2. A method of ractionally liquefying gases, which consists inexpanding adiabatically, successive charges ora mixture oft two or moregases, and e'ecting. a heat exchange between the charge undergoingexpansion and the next succeeding charge to be exanded and therebyproducing an accumuative lowering e'ect on the initial temperature ofsuccessive unexpanded charges whereby the temperature of the mixture isreduced by successive stages so as to separately liquefy ,and recoversaid gases. y

3. A method of tractionally liquefying gases, which consists incompressing and cooling a mixture oftwo or more gases,then expandingadlabatically successlve charges of said mixture, and reducing thetemperaturc of thc mixture by successive stages by efectingA a heatexchange between each charge undergoing expansion and the nextsucceeding charge to be expanded, and thereby separately liquefying andrecoverlng said gases.v

4. A method of fraotionally liquefying gases, which consists incompressing and cooling a mixture of two or more gases, then roundingeach oharge undergoing expansion with the next succeeding charge to beeX- panded, and thereby separately liquefying yand recovering saidgases.

ALEXANDER S .RAMAGE.

